Hydralazine injectable
Injectable hydralazine guidance for severe hypertension in pregnancy when oral treatment is not possible.
Therapeutic action
Antihypertensive vasodilatator.
Indications
Hypertension in pregnancy, in case of severe symptoms or when oral treatment is not possible.
Forms and strengths, route of administration
This drug should only be used by well trained personnel in well-equipped hospitals.
- Powder for injection, in 20 mg vial, to be dissolved in 1 ml of water for injection, for IV infusion or slow diluted IV injection.
Dose
Dosage should be adjusted according to blood pressure. The goal is to reduce the blood pressure to 140/90 mmHg and diastolic blood pressure must not fall below 90 mmHg.
By IV infusion
- Dilute 100 mg in 500 ml of 0.9% sodium chloride or Ringer lactate to obtain a solution containing 200 micrograms/ml.
- Initial dose: 200 to 300 micrograms/minute.
- Maintenance dose: 50 to 150 micrograms/minute.
By slow diluted IV injection
- Dilute 20 mg in 9 ml of 0.9% sodium chloride to obtain 10 ml of solution containing 2 mg/ml.
- Administer 5 mg over 2 to 4 minutes. If BP remains uncontrolled, repeat every 20 minutes if necessary, maximum 20 mg total dose.
Duration
According to clinical response. Change to oral treatment as soon as possible with labetalol or methyldopa.
Contra-indications, adverse effects, precautions
Reconstituted solution must be used immediately.
- Administer with caution to patients with heart failure, coronary insufficiency, recent myocardial infarction, severe tachycardia, or history of stroke.
- May cause hypotension, tachycardia, headache, and gastrointestinal disturbances.
- Abrupt fall in maternal blood pressure with placental hypoperfusion and foetal death may occur when administered too rapidly by IV injection or in overdose.
- Reduce doses in patients with renal or hepatic impairment.
- Do not exceed recommended dosage and administration rate. During administration, monitor maternal BP and heart rate, as well as foetal heart rate.
- In the event of hypotension, administer Ringer lactate to maintain diastolic BP at or above 90 mmHg.
- Breast-feeding: no contra-indication.
- For administration, only use sodium chloride 0.9% or Ringer lactate.
- Do not mix with other drugs in the same syringe or infusion bottle.
Source
MSF Essential drugs practical guidelines (January 2026)
This page reproduces the structured reference information for this batch while leaving out the Storage and Remarks sections.
Rate this guide
Be the first to rate this guide.